This is a weird meme to me. Have you ever made something like a simple accumulator machine out of logic gates, OP? You literally just program them in binary, although usually the instructions are expressed in hexadecimal. You make your own instruction set. When we did ours in Compsci foundations I just decided that 0x06 was going to be my jump at negative instruction. I could have wired the logic so that instruction was at a different value, it's literally possible to make your own instruction set, then your own assembly language, and then your own compiler, and your own programming language. People, mostly women at first, did this for every new computer their institution built at first.